lookup_slow(): bugger off on IS_DEADDIR() from the very beginning
authorAl Viro <viro@zeniv.linux.org.uk>
Thu, 14 Apr 2016 23:33:34 +0000 (19:33 -0400)
committerAl Viro <viro@zeniv.linux.org.uk>
Mon, 2 May 2016 23:47:26 +0000 (19:47 -0400)
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
fs/namei.c

index bdcea8a..c275635 100644 (file)
@@ -1603,8 +1603,15 @@ static struct dentry *lookup_slow(const struct qstr *name,
                                  struct dentry *dir,
                                  unsigned int flags)
 {
-       struct dentry *dentry;
-       inode_lock(dir->d_inode);
+       struct dentry *dentry, *old;
+       struct inode *inode = dir->d_inode;
+
+       inode_lock(inode);
+       /* Don't go there if it's already dead */
+       if (unlikely(IS_DEADDIR(inode))) {
+               inode_unlock(inode);
+               return ERR_PTR(-ENOENT);
+       }
        dentry = d_lookup(dir, name);
        if (unlikely(dentry)) {
                if ((dentry->d_flags & DCACHE_OP_REVALIDATE) &&
@@ -1618,17 +1625,21 @@ static struct dentry *lookup_slow(const struct qstr *name,
                        }
                }
                if (dentry) {
-                       inode_unlock(dir->d_inode);
+                       inode_unlock(inode);
                        return dentry;
                }
        }
        dentry = d_alloc(dir, name);
        if (unlikely(!dentry)) {
-               inode_unlock(dir->d_inode);
+               inode_unlock(inode);
                return ERR_PTR(-ENOMEM);
        }
-       dentry = lookup_real(dir->d_inode, dentry, flags);
-       inode_unlock(dir->d_inode);
+       old = inode->i_op->lookup(inode, dentry, flags);
+       if (unlikely(old)) {
+               dput(dentry);
+               dentry = old;
+       }
+       inode_unlock(inode);
        return dentry;
 }